SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b713dfbd73e02054b5401751b86c98176f7f96f781449fcb000c0ef59b9cb972' 
  AND token = 'rCwPmUzWNHLxkNJL7ScdEsfwa1YA7Dkc0K7nldpUKwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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