SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfa3044146dfefda4410cc54a62db358a661d6e0dbf3c666a44fea52a0af2a4e' 
  AND token = 'exJ2qGmqekSaurAjSvogz+7ll7gWRwNtcvDv1uqpCxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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