SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433e535c83c98e517aac01696a4184435e422a8b4aea892ea071ebeb05b3fd9a' 
  AND token = 'Dat6HHhr4bpBebtAcsODb3YoEHIwfIrnkzALShjhZ7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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