SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ebc8ab1998b2985c93abde81513c0421622d765b1be6578f6ba9ce444631a04' 
  AND token = 'BJOeyuZapq1L5pn8Xjhzaei7w+PbojqOpiHRG6qhO2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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