SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9112fd22964bcaee31573d2b3d4eb8878b5250fabc115a1d937d29eff3ba5f79' 
  AND token = 'H7diI2fApkGtO3BYmxG1qcxzFuMHF4fna+tK5MobJ/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}