SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1447d189052275ba32a5b8195d9f7440fe1b78ad0930299762031dcc5726c84' 
  AND token = 'lqiGFnSIfbBc+E3h2ACjp9DVr62tuXaLxIJg7v9EAgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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