SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26199fadaf79b3fe7bfacd917fab7f13d0c669c3f55a115968802a719a618bb6' 
  AND token = 'fuk0GjmYbT60SNSgQTCPv/GWsjV0mR+AFSEdEC8UoLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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