SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cc09274fab536778ac579fdd9977ab64808118fa4217049d414f66aefc103a5' 
  AND token = 'iRjRuUfaiIWc36CJ+gUUe7n2/OMXxM+fJa783+HXkmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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