SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61bee4f9dcba0590ad66be1f37b3da6552257668cc0f0064679fa65e7603ab58' 
  AND token = '9g1OZVLQEw0U320folA0ukEzqkHbBhOXWttFT/m6wEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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