SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0263b52adf4875681a9841cf7a9b4d7401f1a106dad408c7bdd163e0489f5af1' 
  AND token = 'wNMCtItjGbh1hj+Rhfbo8cldcYmpvw/HGjJJ3um0DpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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