SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03e0e8f86bf5c60e286a6808a23948423ed907083d768629e0b9cd75a7793c88' 
  AND token = 's9ClOXS4Wt8LbkToPf0bYezfoIjWl5Os51Kf3/J8Mko=' 
  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"
    }
  }
}