SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45981243686a3dd55bbf49af2a70c9d2e2e0456926d2206895c94cc0226dde82' 
  AND token = 'YDDkyh/GFEXkuhfqxQViImcWENYrskdU+e5dA1fd8yA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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