SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '532a86a021f50bf7cd2daa0f309290d6b853731a6acd030e894ed5fabb02248a' 
  AND token = 'uPxcsZUrZee7TMqHYlfN0TqivowYT+flnixLyLxw69U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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