SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd22683a1eff217f5bf9209721f16702d460ee95f9d81e430210082fe0360b9b8' 
  AND token = '6BBTFHU+UE1SQoyUlyfUKux9kJBDq5nu2lW3pTCaZiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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