SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f98a8a7cfe568cbd13f5e0eb4970a995bcfd560d953c68eea23c282e553868be' 
  AND token = '2FmdRFL7Vbo6WMAu6aVjvx0v1QIeixQ6PDPzoC5RPao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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