SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95bce4a329bf476c722f5b0297e66b5e13988e59213cbf6aff8f24259561dfe9' 
  AND token = 'p7+/7sGhQNHJqp0gqqJlvXdaHN3zTtyWP8Ch47dhzz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}