SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c194ef6ce6806ebadc13dbf4a388760e509590c08874e674a89e0dc555980874' 
  AND token = 'nsDDMYwuwqD4TB14qjQ0RHfjGSVZESzk8JGZYvyzBuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}