SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ece7fcc85164f782e8178b2cb7a5f47df06f48545dd67c689602649a2e55eb34' 
  AND token = 'NxIkVFqsRPATl4FUrcwYeR/rzEf2Na3260NqKr5vAqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}