SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2d5cf04b92b7fa2857b40beaa17f560f977f5d1e3fc1e68a237f6f5d1fd97a8' 
  AND token = 'WPDqYCDpq0UaPPjWuZmcmX2RxttrL0ZlPpAlRF35aWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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