SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1b42d9163b117cfcf894384f25dad858e5fb55225d0127a7be50f8a4a91bb16' 
  AND token = 'qSoX1je8rzKW1wQXSlGhMR4fxRWNEKwMPS6m28Cxodw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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