SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d1dd70a1a118199eb88593dbcce090a9b03b6f69af5924cd15cde2d0a68c7f' 
  AND token = 'jalAPLgOyyctm8iWMzio3cgWMWu3fDadvC64GcGA50E=' 
  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"
    }
  }
}