SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97047095ac1a7d7974d150d29456155841c382f62a3398fb1dfa3a04c0b5294e' 
  AND token = 'ZmJCAjrzhHf3uRzwFc8+JsI6U464jgrNtklQQE8jI+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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