SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12ed4be8f3c9af32275b60752e57072f2d49acaa2f43bc2a980221a3d07f04e5' 
  AND token = 'OqrBUw9zBjrlGpX1LmZrgTviDmz+YuO8waNj4X2Ivqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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