SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1170fcac521ca57ef780712feb8b591fdf6f1dbad2e356dd8d23db96ea67b42' 
  AND token = 'KnxqbtJHaW7heAeuAXzRwpt1M9tQqMAPFpBQuURES7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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