SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18900ab153697bf4cbb3183f7de1a604d90963fd74f449bd9acdbece8c57f6a5' 
  AND token = 'GPPkwrCN1S5ZjlNIw60/oJERtl4L13nBa2LTNSq5o3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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