SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4379275b1ef356da0559fa836baf502477e51924d1182262303568c47b75ed27' 
  AND token = 'zy/y6o9zqyL7t0+g4pA8x8V2SKZyhwd3v2H3rAolCPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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