SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1f85224a483b448459998354f61f962561c5ed61571c20f091ef1b46edd8e72' 
  AND token = '2T0GD/L/nxHdBvgklRy1q0NvcpGLOwdyfhgpVY8tUns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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