SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d3102fd816ec468dc7c2979c76534cad91928cfb93f65486abf5c7c331d95ee' 
  AND token = 'GE47L2gpxELEnFxFsmvL8/8UPkAu0EzLyhEGLgtooeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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