SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5015a3475fbc5a8905258a30c41785eed5a24844f1692b1b7cebc4cf04e2e57' 
  AND token = 'MLPoSsD6sjueOCm5wofdTHVDF26XwmMptKTtvF2lTHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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