SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c0b7d985b1130c40c606d46966c5a50ac575bcfb1d7daab96cf34d4abcf1df' 
  AND token = 'O7ecQ/HTutTqnJrWWNef069uJGick+RQ/fQoQtDbgPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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