SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d3a8fbd121ba07f402cf88a695933534e4c77c2342b94d5d2b08f66ccb684d3' 
  AND token = 'lEXLAreFN9U8TTX170tidsRIfPihCFGediCspIoQo1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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