SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e64bba2a2ccbe6d5740902a9677b9126c3b36874c6ba6b89fdbcdcf9b406f37' 
  AND token = '2r9Uhr2mi40KT0EtiF3IyXwv4DbwdTsVxCMQ4brUpUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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