SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9c56beafc581067220fc0671bdbe97a96c86f382e17b88e9a57613fe5c779f2' 
  AND token = '61BmSuizsN6Iz7m2/Snrg6JTHT1+o+N9DK7k6I0nkzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}