SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b14fb081c646eff7beedc518c9ccf96e09515fda43f2c9be172fc582b79e3c6c' 
  AND token = 'pOf45mvCb6cwcsf6w82VV5oAFRwlvn2KnXyBWRElzFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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