SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a390caf42e9f4c7406913170392ff74cdf3a88c87f05e855dd3302f08400150' 
  AND token = 'Fg9MuSjlKeYKwrS4e60LUROGQoKPuyRKs/zbwEbWzE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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