SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cb1420eb90bb7934799106f4c580c1ad51e95881ddaf4de3aa0230670589e63' 
  AND token = 'm46i4cTz9dFZx3jZRyRvWE9Z+teZ8KHGvW/XKYgqnDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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