SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efcb70c04cd505f436ac16d36647b8134614ab96e64b6644ee9a6746d5cce7f0' 
  AND token = 'yIGFJY2ZJpOF2bjhOGqd3pJtbv9SfKMeT9TVEQVgUJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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