SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8065a81ac77adbd845b4143a4645002d809431057142e9ea8aa0194cfd02aed' 
  AND token = 'vsgiX6IuQILmlN2Xr9fFukbX96RJL/z0hU42msON0f8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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