SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0945a999074efa126bf56bb9047e48a8124365e93cc53034d2bf44649023ed75' 
  AND token = '3ORzqayEguuxKu7l7TANP4JE5hKhvkSqu5Toh5SRqHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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