SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de60648c78af53672b799362888a4677a14dc070e63761bc8b194d3d3a6bc55d' 
  AND token = 'bg9ykhCj8mhCItgxJr/OXhPJjrYWXAyuIOHxvnBOH7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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