SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '19d2d49a47bd456834235e54b79ef374f9b90c0503f53c8ee9f048d9e6be7353' 
  AND token = 'G3Z37+XbP12BDHi1xeStYGV04JDHgV8OD3JlGMMnhIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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