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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29ca2065d2b721fd6e78c4aa0a8d1e6089bd016e0bbd8fcf04a1507e74e0aa46' 
  AND token = 'lm2At5I5bVrqOdWdy65RdIEF8JdchkAP4wDh3p0q2CU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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