SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7c7a6a6d57a4ebbb97ea73d97fbf0079189fcba614d14b59cb25864b0d27ede' 
  AND token = 'IlLbd1jtC3V/vbBhjKebtLypYlhOEZ7aD3bAxOm6rSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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