SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '336fadad8cf58ba44dbb8df001754801a8a1bb825fbb0ba02313caf73e93183a' 
  AND token = 'yPSkUz2i8eO9hgcIgb0gOyPcexBtJrAHjFpbOQi4F50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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