SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '467e0f1c1dfce6aca314d1358c72c71f5bfbbffd06cd83069b1dc27bbf413934' 
  AND token = '/pirNzzBZhBIZHbuMMP2HjTPuizWgKGTsS7rOi+itVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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