SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '919f5622e8833829a2ee2db8d4c9f058ef6d40344d6043226b5e7a51195740f3' 
  AND token = 'gUIsZmfvAd0M1SaHfLGTBkWiXwm/CtsQ5FggXaJBa3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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