SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34830ba25982c26b0d8c61a34a30365a21a33952f4bc385cd1f1f88bafc430ed' 
  AND token = 'ia2/RljlWhTYLl3lqoFFhgoOjVQcDzSx1Rp08nlQTZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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