SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1beaaebe7614d805bd7cf23329197250231492ad4867c18ac7677e48d3a0ed14' 
  AND token = 'P1ZHtkcDREhkTAYnU31xcZugfGXe/mEYqlO6V2DNR/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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