SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd39bf35e009e4049c60cb368f851d56ddf84002c2fa84f931025865dd3125db3' 
  AND token = 'VyKwFN7F1VlxV6QJ6YbWlzqHUgMjeV7E+nsNXN3Yq8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}