SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3057352e5391299d2e0cca3c8dc64cef0a5c891c4e4e4bf7adaa35c7136bb9dc' 
  AND token = 'mY1GA4HmON5jyjRL++pFWYgDOkW5Omittadv6YcsBn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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