SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20a7638496f0b4663cae8dc5ee454240c6ae5da67f288e3d4fb2277d67d52e6e' 
  AND token = 'x1Eh2TYB2VUPvlbn1EkFL1fbiBUlMtxJvv322xmHtJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00095

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}