SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f1a6b362947d6e99e0d8123e543a7b9e4109483de1ca9d622807737c9e0d564' 
  AND token = 'Xs0himPMhTc9BizYxNvW+vfr1DmYEvhZrOK98tKmh1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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