SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e0ed2ffeda9f759450077480be8b60d69b49166647496cf3dc87e3b372bf591' 
  AND token = 'DbD/nv+XfKzXLnHQULylzOm5H8VKjxJR+pEcSG4ag7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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