SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f37e59d78c1452b95176f90fac0309851c02616b74221fbb711c9c6ddc036db8' 
  AND token = 'aVWO5gZcjxRif33YmWCVV+vmbXDj8M2qMqgnuWrQecY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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