SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ca2b62f809f75bc53df9c03747496fb9f9f625bfd67603b52f3ae6bbc7a18bf' 
  AND token = 'aM2LQGcOIWKhWm9REGHQ+KlnkaWkOP+gsSmOXFMOAuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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