SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e788387fad572f767f31974284e406593c82d036bcac13935a09d7644eca0d9' 
  AND token = 'Nq/B17bzdjy6KwQ/TBjqrXm+C2d5Qro3UXuDhYSu/1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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