SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9048d6f717d1a742e6ca0c646e9edd2f90fc419390f652bd5d1b5181f40023b' 
  AND token = 'T/WUOd5pXTNz+9SygTgFW3lqMN6iWY8pNwoXGu/ovBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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