SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c377433e885295467b146aed1c718bc7cd2b1199f342b588aab8f918a26e91cd' 
  AND token = 'BjHQEFnuJ+z/hUTw41d/u/TjnW4Voa7t/vX3ArOrnzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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