SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab2d7cb8a3da6f386b29552ed7ae0fba6affdf0ffbe2cb258fcc306fc59cec0' 
  AND token = 'AjlUpIsMIOmnZeG8OOfwXo2M9EXdZZMbGEpAMeHiNWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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