SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe94de7ca2edad7c2750ccf93cdd583f86019e6aa2ec4866bd922ff1864ee864' 
  AND token = 'RZn44ALgfgVmoPVXm9tul3Ah9+CCpVuaVq4VIOKN074=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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