SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '242aba8d262d6383c57b9d64bc0b6d4091c88ef178fdd96b0c517171c099f77b' 
  AND token = 'cDlHBEdbEpsztiHPKNwcEjWw4xTfbG03JD9XoMhHOh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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