SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba61cfdde5058f5e82cd749e03bdbf875063f78bada8f01015ad144af508258a' 
  AND token = 'WLndzXF7qJASODOQALeAjhHnMOEWnglnQp0g0LVhqv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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