SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1929e9249ffa8414aa62eb87b18c6389979c58d151052e96aeccef63a03a144' 
  AND token = 'LX2lRvXquFcmWF8AI1ncqo/EpqAA2sXA0U1lga9l8+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}