SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36289695ca1a2d1c8977edbfb8041903f0100e384afa8b4a59efa9929d81cb20' 
  AND token = '6YtNFgABbw5EQZGuL0kMkBm3Gk2/YkFkSmh6J7AInUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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