SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80a771aa63359b46453334364b7b4e4468d9cfc6f5f97a85ab7c08e162408da8' 
  AND token = 't22P+RQJ0Rezn8lgjWltRl2h5qs/7vxa9uNpfR65RFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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