SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16dd7ea000696e6eb9085d3dc3eaff7d5a882759dd583483413f1c8e026b555d' 
  AND token = 'TFM2S3oIv6+7jC1s+47eE+HMV/BLK887MaqZCnUIzX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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