SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d40efa60badf110d4c6208ea6c7f4371c5d2e438ebb8cd00ff89978e7e749ad' 
  AND token = 'eyJr6CwXMbmAjaxl+Vy0iaimN2f2HsUsnE2929mEkfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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