SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2be1db01a06750235b08b0f48f4fb6c46dbac8226285b0e0324e79b425ebf805' 
  AND token = 'moR06Mb/GVDmgK04ZphKKXNiVbMnkQ+7v3NwzTLdlb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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