SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3adafef5f8e26616d594ffc5275dca1304f44bb5f1027a33696a54277e2ddca1' 
  AND token = 'Wane5jRiRCgSV29Gc6PdanIt6SI5t8u/YeTqArM8Bg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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