SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6bd8f4ab69d5ca49ab06306d3080db4c538330560ae331a14ec5d88b9423226' 
  AND token = 'JKyCmJOe4+Xd3EBWhCVtIB95vFUHZz6qFVgPfeKIxs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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