SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6c633d208957d6c8885080e5c3794dc458a3357d2a14c8dc837842ea98ab98b' 
  AND token = 'IFBSGNVygkwuxgXUofTPMCPTaxysIwIJNYijb2aw30w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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