SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36e684af16df7ad852de866a50c10dcaf20652071144bdeb3de3a989113a5c5a' 
  AND token = '1biZu1hyYgVz5EhMJLLJHkSKyfl4jYNKXO/+QIBmvi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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