SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb43d7234e839e549784e197fee52ac6dd473a39182cd79412199809681ffc51' 
  AND token = 'Ry15UJ9AWxHhaiSP1lT0LW7v682nhNHcnpo6xVvLko4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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