SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad2c7482e251dd75977a9446fdd7b18bc944daab3d6ca9b2a8530fd106190540' 
  AND token = 'lgWhmT0ayMNv828/fsGdbNCV30Qv3ifFH8Ud56OXItg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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