SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83634700738bcdfdfcb58ac310db1f8504b054f286d59f527888e664b3ba4888' 
  AND token = 'EFUw1WrwW0Xmus/ysQgJlKqFKAGe7xI4shsCG+8hRoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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