SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc7f6af9791321581038a1da418f6fec0d21cc2c723fcd3948432c37adfdc4c2' 
  AND token = 'DDEGTzcpE5wVqlB062EBW+qg5ItA6TgWyDZayRazXrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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