SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a0ab037a4be033ae4f98cbf0c88c34be80276bd96ab9885a6a8669f86092a8c' 
  AND token = '6VPK9EPstDhqNHbzKzQZcbdvUdt5C/IUD2L6ApNGXmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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