SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc91706dc9788e1f8e8b8bfb4e189b3ad64295401fdb04445c88dcffa80690fd' 
  AND token = 'GeUb/JjSdcUSiivEOcPve5HQGlw6AVUBD6yOu3+oRgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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