SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b06a8d40a350357bc67acb23d54934f2c099862068ffdfcb3b17e1beb61269ad' 
  AND token = 'EI2EqNq+EOWAafNrPlODmgRkGNFDxS0/OLhwvmbJNeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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