SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '564e0fb58275bb647bbdea745011170ad20b5daa2d0b680c0244ea67f5964477' 
  AND token = 'Tom4505X9qsrVFYSVQEKlDygqWzxQt/9ZrVkOSm/OMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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