SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf0f6208ba1dbb86ea2307f81252c7c856b596420c9c0262020cf08222c9caa4' 
  AND token = 'GZaaeeP5JTZ3eaecOri40gp6rnBmqQz3zTSlOPxlisg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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