SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd38b0452c19a1567878f58246c4d66ccfb805934e1616869b167a0ffeac7e2cb' 
  AND token = 'J5pR2Q307k1Gewchz7NjJ/aEPWdhtT5BqA+YlzwKpoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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