SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e037e6f020178572c0d45018977e3be96a789051832590e32c8c2f791470bd05' 
  AND token = 'LOtkLWvnE0ZipzzmpQF/hlr0Ja3IO09FO766usGh3rE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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