SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01e7dc6ac3f69b717baf66ee1020c9832f155d1228a81f0a4186b3cb510c2018' 
  AND token = 'QVkq4/oijArXoESKlq3sUn2KSjB3+iWD0x49LjG2mFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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