SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eb93a447815b934a8c36dce4d2a5a54be4896b84c459f259079a481eb3c9954c' 
  AND token = 'FqMYzBwVayVkhFpJGOQZsCtUdzJtwosIZjoT8myYAVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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