SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbdcfbdd1eefcd44b9bf881c4ef9f0493d1e0971bb1fd862f3b9d70a03e52cd6' 
  AND token = '1JDuroHPKOY4Q7CwxjqxCrLtyxRkD/xWpxVjhGOVCPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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