SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c433fcb949af57d4161d767537638217f1e0284272575db90d4e1ec041ef10' 
  AND token = 'rG7OaVIvt/Ych2BbQZw5zNxqIMEhjmSmUG7uuoXIPvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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