SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d06dc4303088abe9b3ad24aaa6bf048c0588c9b79560cabb393f10a3ba95387' 
  AND token = 'RjcyIRzfFn9ZyPyeyil3fERQQ/J+tvxUjdhg/S+OmfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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