SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4f105dc03ac150a52aec6ce5bcdeebfe7a92c4aecebe7a4dbd548ae80b3c893' 
  AND token = 'HxpDHZSUDzLvY4vts8wNZruqdHxeMWXSJhMH5OKgCBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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