SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864853cfca78b7f2d063a4e201612509856053623a45cceede5430100ba41f12' 
  AND token = '9AO9MIulFg1J+Ph0+l81fx92V44d1GKf5mEghnqLdxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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