SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aadeceb602c9c49203007ccbe503df02fdb99c855c1a55e6f5917a82d3ed9b7c' 
  AND token = 'j2nMoXN8ee7mTf6tsyURE+YbLpkqqBAdjuxIEWl/OnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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