SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cc2884335dbe1a27e579c5819112cecda73198acf9944c2b049bd6a8d6661e0' 
  AND token = 'WfLhoiw4lPezxNSkayGt4TnebyOEvO6xUmFIZzeBIJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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