SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b536f57b41fbe9214c751fcf35c7c9fee0400d2fc9c3fa8589fc190c79becee' 
  AND token = 'KF+mmY+BsGcZWqL/lQngHydLbh/XxxK6uQVnk8cN7gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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