SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '648b5fa43b7d3a0266e888ced464a4164022b7894706b22a7f94fe649095ebdd' 
  AND token = '5HN8p8RX1r9oAOeBZ3vP4AF0abpjeiGGNlhBYegXY7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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