SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b236dc18b08007aa0a5f3173972ca1f4b4e1f9c82cbed269a22ad6ff6bc81f0' 
  AND token = 'LI2IL5s3dvVznQhOheEFg9E5rglQcqGXRVhU/ajSGYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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