SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9aeeef04ecb18cea639a188121cd32b00674d24b301e7bb121a46158fce709d' 
  AND token = 'hqGB+JU8cjwTjVtR+zOAEahOahHTo/VsgzRP+H+ZVrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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