SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce4b5a69c4dafe4d31e608e164b5296bdfc635cb185722de7ddd3e706f5e829f' 
  AND token = 'TKDr/2ug+5Cg34upVw8ISZ5h2Bn+OTr/2N6mTOHQXd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}