SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79dfea927dab15c1813b3dbbc60e80f126bfc427ef3f7a8c3f6e88786883ebac' 
  AND token = '9xWR/BKX9j8ONeUwl9jlUV6JGQG5ieIun/TmPSYZkJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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