SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd09cd04895e16b62c3513fc2130013a35b20f31f168643985c8a22efabe45574' 
  AND token = 'Z4ky6lKmqp48VhymSymUKMdEAWnpkhpLihaSiVBepB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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