SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b8b0a91e08eef18f282c387eef5f07995223681d7de6f6ce53ffbf2cdc6e70d' 
  AND token = '4HPwmB6T+xkWm7q1zVN0QgoXhEGZUjtJVbd6FxHDfPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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