SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e8c2df53a42fe96815373cccd437f55add7e517a7a9b840127bd28560924ec9' 
  AND token = '2HZ+9EhXsjNkvnZDKq7bu/a+TlrF/3zDR/WgmoU4qEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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