SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38171047a448b1fe3949feedf565c763fc9084a18c4dd658d03f3a6697bbcf88' 
  AND token = 'YVqumvoKItmQgMJYCpsvcnkZWzcxIM8sDIvsRz8GivI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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