SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e54e2e0487bcf9c78757f5df095650427ddee687cd36a5bfcaa48b8f5591f52f' 
  AND token = 'mAEHw14rWSFIs0bgRZWpDhwV887ESeNtrUqLM1wtZxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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