SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6dca88f6e724f84817893b1afa77826c4197a6006a83f2d5a146017e9311470' 
  AND token = 'ugXAGd+eicGBc8N5Y9+tUIp5CIufM5lWPlS+4PQm/0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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