SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c546aed0ef334b4a9b02b038b749a97e827366ef91ebec1dad52c0d09e74590b' 
  AND token = '33koBq6xIGmLdQvzK0iPT30Ykjd6vNHibX5RtvrswEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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