SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b98114dc7a5f6e231311fae639a7666d78194564d6124d87cb734c2c61308320' 
  AND token = 'rLmt3FYzUqHAkrEQu/qyEL2hE/HMreTft3E3JYmiKDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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