SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a628cf03c5c0364361e1192a57392935444ef632ded9dab98106c6a0b39d1d3b' 
  AND token = 'TNfFNWsHynwq8l6jWzqe9Ldm0UaNRQT64hOj5VuzNzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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