SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45d4bf7e4ee4814b1590179c8975dae71a1b5afe412098955765966b45d846cf' 
  AND token = 'wjuTWNCyh45vyDBBFKKPehL8pz0OsUuZAbSsXEgcEys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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