SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cc2bb7fc3395d77f5f61213de7451645314a733b0fe0cd38624f6acb88fe503' 
  AND token = 'YGWt9E9WMeEDjY/a+In5WU8yZLI7K4Hpr1TigIBU4Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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