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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e08c38de9b4225537f66a79ca62ae7591bd38afee7975b0b8e4eb749680f78f4' 
  AND token = '+uw2NVziZjtfG3k9lMgdEmlE/L553smdbXqbc/e5D2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}