SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b41df46a2efe6c6a491b5efa927ae358768f30b36230c36f4832b56a8b41343' 
  AND token = 'q+v8E5LTI+n0eDnBKlUvUObGiyyyzHREQqXnkFLzYZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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