SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6de0d2a55acfe9fb67607652d8d63ce338829051f171c723058bdb8b95ab79e7' 
  AND token = 'wDyo9V+BhK7TUOVDpmR1peCxREKscysBw+T/nKkx/P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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