SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58ecc12b8ef1c677fd5e0ea098d6811282c75b50470ed06add6dfa91707d7943' 
  AND token = 'oRxMVPYhYVhzwzhJ8qFnl9xow/M6AOLBjXluzYsK4xQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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