SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '441fced646b7eaa58c4889fac500d71ff797c8ff585de7af83a6f99ff0945e1d' 
  AND token = '4aXZ/dPtZyElcLorH92whR3g4vVwKXKHqPRCzwew3Gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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