SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce227e311be0918ba63d6e6beb986e84d2b8d79c540103d3123ba3753a62d476' 
  AND token = 'sHpN9vOLQlr5+vQp2Zw2MCqWg3aZmZSy4LNIlHQyrz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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