SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc48b5784e7d3dcd13ba99236643f609ce1ae8cf7ac81b68f4705818fd6a1912' 
  AND token = '8XvO5fCrREcpzi4t38vhpnmeapBi//gkcGxYjSKhynk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00077

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}