SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '258d16517c5835d78a5d3d330ddb49f8096c919ad17ad40f219141a8b915b35a' 
  AND token = 'hqyzjEZRMPmunJsq06mEisphaCxUvgOKe9HjOhsaHmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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