SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '519ad3cc43e806b3e6ae4c3bc20261d5d0db511c0067107e2ffe2f5c1ec0a1b2' 
  AND token = '6hwlWQW3B9LmjJ5TFXZpvyKInQlVV3wDQHmHijOHsbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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