SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0560000587ff6c1ad9919295ab5d466235fffaaa3839dd83655b983bcee6db13' 
  AND token = 'n7EBLDa9QDBNFgspTY1kDC/ZwpPax1+HPhwCkf7rDjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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