SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '452f0f9559884fcaf14164c9706356feb419bee1dcc488a51338ae2b7695a912' 
  AND token = '1Zg+knsF4Yjd7bDkGVK9row/edwALuzrQV+skSlk804=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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