SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1833b4c8974fadf5610dd118177284a3c1f77a652fb51e34d26a760df31c2505' 
  AND token = 'JSl7QFrvqq/zQhn5kW22Q4Om7QybwBIXCzs+kusc9PM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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